The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Electric vehicles (EVs), hybrid electric vehicles (HEVs) and plug-in HEVs use multiple propulsion systems to provide motive power. The propulsion systems may include electric or battery powered systems that receive power from one or more battery packs. A battery pack may include one or more battery modules, and a battery module may include one or more banks of high-voltage cells (or batteries), such as lithium ion cells.
The operating temperature of a cell can affect the lifespan and performance (e.g., charging and discharging characteristics) of the cell. Regulating the operating temperature of a cell within a predetermined operating temperature range may maximize lifespan and performance of the cell.
Within a battery pack, however, the operating temperatures of the cells may vary from cell to cell. Temperature variations can arise between the cells of a battery pack for various reasons. For example only, temperature variations can be caused by manufacturing differences between the cells, differences in locations of the cells within the battery pack, thermal path differences of each cell, and other reasons. It can be difficult to maintain each of the cells of a battery pack within the predetermined operating temperature range.
In addition, the cells within a battery pack may not be packaged as efficiently as possible. As a result, the overall height, mass, and cost of the battery pack may be greater than necessary. Furthermore, high voltage connections within a battery pack may be disposed at various locations within the battery pack. The length of wires routed to the high voltage connections and the number of protective coverings for the high voltage connections may further increase the mass and cost of the battery pack.